"Feser... has the rare and enviable gift of making philosophical argument compulsively readable" Sir Anthony Kenny, Times Literary Supplement

Selected for the First Things list of the 50 Best Blogs of 2010 (November 19, 2010)

Monday, July 26, 2010

Popper’s World 3

The Self and Its Brain: An Argument for Interactionism, a long exchange between philosopher Karl Popper and neuroscientist John Eccles, is among the most significant 20th century defenses of mind-body dualism. I do not agree with every aspect of their approach, but the book is filled with interesting things and deserves more attention than it has received in contemporary philosophy of mind.

Popper famously distinguished between three “worlds” or levels of reality. (Though whether “levels” of reality is the right gloss on Popper’s theory is not clear. “Kinds”? “Aspects”?) World 1 is the world of physical entities and states – tables, chairs, rocks, trees, fundamental particles and forces, human bodies and behavior, and so forth. World 2 is the world of thoughts, sensations, and mental phenomena in general. World 3 is the world of scientific and philosophical theories, arguments, stories, social institutions, works of art and the like. World 3 differs from World 1 in that the entities comprising it are abstract; for example, though a theory or argument might be embodied in a particular book (a World 1 object) it does not depend for its reality on the existence of that book, or on any book or World 1 object at all. We could still consider the Pythagorean theorem, know it to be true, prove it, etc. even if every geometry textbook that had ever existed were destroyed. World 3 differs from World 2 in being objective or public, whereas World 2 is subjective or private. Your thoughts and experiences are directly knowable only to you, but World 3 objects are equally accessible to everyone.

The objectivity or “autonomy” of such World 3 objects as theories and arguments is especially evident in Popper’s view from the fact that they have logical relations – and in particular, unforeseen implications and unnoticed inconsistencies – that may not be noticed until well after we first consider them, but which were evidently there all the time waiting to be discovered. Naturally, he takes mathematics to illustrate the point vividly, but it is in his view no less evident from empirical scientific theories. The clearest mark of the reality of all three worlds is in Popper’s judgment the fact that World 3 has a causal influence on World 1, and does so only via World 2. For example, the scientific theories which entailed the possibility of nuclear weapons have had an obvious impact on the material world – they have resulted in various nuclear tests, in the destruction of Hiroshima and Nagasaki, and so forth – but only because scientists carried out the mental activity of working out the implications of the theories and applying them.

Popper’s World 3 is often compared to Plato’s realm of the Forms, and Popper himself acknowledges that there are similarities. But he also emphasizes the significant differences between his view and Plato’s, not the least of which is that he takes World 3, despite its objectivity or autonomy, to be something “man-made,” its objects in the strict sense being what the human mind “abstracts” from their World 1 embodiment. Though Popper does not take note of the fact or develop the theme in much detail, this is clearly reminiscent of an Aristotelian or “moderate realist” approach to the traditional problem of universals, as distinct from the “extreme realism” of Platonism. (See here and here for a useful short account of the traditional Aristotelian-Thomistic-Scholastic approach to the issue and its significance.)

In other ways too Popper’s views as expressed in The Self and Its Brain overlap to some extent with Aristotelian ones. The emphasis on abstract thought – and thus on what is unique to human beings – as what is of greatest interest in the debate over dualism is very much in line with the classical Platonic-Aristotelian-Scholastic approach to this subject, which is quite different from the contemporary obsession with “qualia” and the like. There is also Popper’s acknowledgement of the reality of “downward causation” in physical systems and his consequent rejection of physicalistic reductionism even where non-mental phenomena are concerned. And there is his affirmation of the existence of objective “propensities” in nature, which (possibly) hints at something like the Aristotelian notion of potencies. (Though these last two themes take us beyond the World 3 thesis itself.)

On the other hand, there are some decidedly un-Aristotelian themes in Popper as well. There is, for instance, his denial of substance in favor of a “process” conception of the material world; and there is his rejection of essentialism, which he seems to assume is inherently Platonistic and committed to an a priori or “armchair” methodology. (This is a serious misunderstanding, and a very common one, which we Aristotelian-Thomistic (A-T) types find it rather tiresome constantly to have to rebut. See Oderberg’s Real Essentialism for the most thorough rebuttal, and pp. 30-38 for a reply to Popper specifically.)

All the same, any Aristotelian must admire the non-ideological character of Popper’s approach to the mind-body problem. Unlike so many contemporary philosophers of mind, he does not fatuously pretend that a presumption in favor of materialism has somehow been established by modern science, or that dualism rests on “intuitions” or the like. He does not present the problem situation as if it were a matter of determining whether we ought to wedge the evidence of our ordinary experience into the Procrustean bed of naturalism or instead to lop it off entirely – as if these were the only alternatives worth taking seriously. Nor does he have any theological ax to grind; he deliberately avoids getting into the question of the soul’s immortality (and even expresses the view that he would prefer not to be immortal). He merely observes that reality clearly comprises at least the three sorts of thing in question and that any serious solution to the mind-body problem will simply have to accommodate this plain fact. As The Self and Its Brain shows, Popper is also much better informed about the actual history of the mind-body problem than contemporary naturalists tend to be. (As my series of posts on Paul Churchland indicated, many naturalists seem unfamiliar with anything other than the crudest caricatures of what non-naturalist philosophers of mind have actually said.)

In short, at least where the mind-body problem is concerned, Popper does not attack straw men and he respects Butler’s famous dictum that “Everything is what it is, and not another thing.” (I put to one side for present purposes Popper’s views in political philosophy and philosophy of science, contexts in which he is more open to criticism on these grounds.) He thereby stands acquitted of a charge John Searle raised in The Rediscovery of the Mind against his fellow contemporary philosophers of mind:

[W]e let our research methods dictate the subject matter, rather than the converse. Like the drunk who loses his car keys in the dark bushes but looks for them under the streetlight, "because the light is better here,” we try to find out how humans might resemble our computational models rather than trying to figure out how the conscious human mind actually works…

[W]e ought to stop saying things that are obviously false. The serious acceptance of this maxim might revolutionize the study of the mind. (p. 247)

Like Searle, Popper is in my estimation better as a critic than as a positive theorist. (I discussed an important anti-materialist argument of his in an earlier post.) Still, from an A-T point of view even his positive theorizing is closer to the mark than that of most other contemporary dualists.

Ed's reviewed plenty of "new". He's reviewed Churchlands, Dennett, Stoljar, and more. What we've learned hasn't invalidated all of the insights of Popper and Eccles, much less Aristotle's, Plato's and others. The problems and arguments they point out don't go away because of the calendar year.

I like what he says, below, about consciousness as a matter of animal biology - too right. But ask anyone in the street if the believe they, their neighbors, their dogs and cats, horses, pigs, and bears are conscious, and they will say "of course."

Is this the "Well-targeted criticism and sense. Which can be sorely lacking in philosophy of mind.", or merely the lack of well-targeted sense in his PoM?

That you have find some fault, any fault, with Searle's thinking so you can try to somehow tae kwon do it into a wholesale rejection of what he says is bizarre. We get it: You don't like Searle. And yet, life goes on.

Also, it didn't take the "quantum process physicist" to point out that Searle's position smacks of dualism. Ed himself did this, even while offering up praise of Searle's criticisms. And he didn't need to go quantum to argue so.

Unlike your apparent interest in arguing just until a point might be reached where you could justify some sort of immature tirade against the other person, I was just making observations about Searle's consistency (or lack thereof).

Rather than ending in a tizzy, I will make another observation: what Searle must conclude in accepting Stapps quantum process consciousness is simple:

From previous posts and here, you have made it clear that you hold Searle in high esteem. I too find him very bright, articulate, and engaging, but must admit that his haughty demeanor and his professional career does beg the question of opportunism.

I raised the question of whether he always held his current conviction on AI (going back to the early 80s), or did he participate in AI research before that time. I think you once interviewed him and maybe you might know something about this?

Does he really think none of the scientists around him at that table do not think the same thing? What did he add to their effort. The converse of Searle's quote above would appear to sum up Searle

JT, have you actually read Searle? It seems not, since there's nothing he's said that recent neuroscience is even relevant to. (In the quote you refer to he is talking about materialist philosophers of mind, not neuroscientists. As you'd know if you'd read the book the quote was taken from.)

You might respond: "But if he's not saying something that recent neuroscience is relevant to, then what he says must not be important." But that would, of course, simply beg the question, since part of what is at issue here is whether, in the study of the mind, there are irreducibly philosophical questions to be considered as well as empirical ones. (There are. And those are the ones Searle is addressing.)

Searle was never an advocate of AI, by the way. And the "opportunism" charge is simply ridiculous. Searle has always been an independent thinker, willing to take unfashionable positions. I have no idea what you could possibly base such a claim on.

It doesn't matter anyway, though, because what matters is the quality of his arguments, not the motives for which he defends them. Asd he'd be the first to agree.

About Me

I am a writer and philosopher living in Los Angeles. I teach philosophy at Pasadena City College. My primary academic research interests are in the philosophy of mind, moral and political philosophy, and philosophy of religion. I also write on politics, from a conservative point of view; and on religion, from a traditional Roman Catholic perspective.